drivers/infiniband/hw/hfi1/mmu_rb.c

   1 /*
   2  * Copyright(c) 2016 Intel Corporation.
   3  *
   4  * This file is provided under a dual BSD/GPLv2 license.  When using or
   5  * redistributing this file, you may do so under either license.
   6  *
   7  * GPL LICENSE SUMMARY
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * BSD LICENSE
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  *
  24  *  - Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  *  - Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in
  28  *    the documentation and/or other materials provided with the
  29  *    distribution.
  30  *  - Neither the name of Intel Corporation nor the names of its
  31  *    contributors may be used to endorse or promote products derived
  32  *    from this software without specific prior written permission.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45  *
  46  */
  47 #include <linux/list.h>
  48 #include <linux/rculist.h>
  49 #include <linux/mmu_notifier.h>
  50 #include <linux/interval_tree_generic.h>
  51
  52 #include "mmu_rb.h"
  53 #include "trace.h"
  54
  55 struct mmu_rb_handler {
  56         struct list_head list;
  57         struct mmu_notifier mn;
  58         struct rb_root *root;
  59         spinlock_t lock;        /* protect the RB tree */
  60         struct mmu_rb_ops *ops;
  61 };
  62
  63 static LIST_HEAD(mmu_rb_handlers);
  64 static DEFINE_SPINLOCK(mmu_rb_lock); /* protect mmu_rb_handlers list */
  65
  66 static unsigned long mmu_node_start(struct mmu_rb_node *);
  67 static unsigned long mmu_node_last(struct mmu_rb_node *);
  68 static struct mmu_rb_handler *find_mmu_handler(struct rb_root *);
  69 static inline void mmu_notifier_page(struct mmu_notifier *, struct mm_struct *,
  70                                      unsigned long);
  71 static inline void mmu_notifier_range_start(struct mmu_notifier *,
  72                                             struct mm_struct *,
  73                                             unsigned long, unsigned long);
  74 static void mmu_notifier_mem_invalidate(struct mmu_notifier *,
  75                                         struct mm_struct *,
  76                                         unsigned long, unsigned long);
  77 static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *,
  78                                            unsigned long, unsigned long);
  79
  80 static struct mmu_notifier_ops mn_opts = {
  81         .invalidate_page = mmu_notifier_page,
  82         .invalidate_range_start = mmu_notifier_range_start,
  83 };
  84
  85 INTERVAL_TREE_DEFINE(struct mmu_rb_node, node, unsigned long, __last,
  86                      mmu_node_start, mmu_node_last, static, __mmu_int_rb);
  87
  88 static unsigned long mmu_node_start(struct mmu_rb_node *node)
  89 {
  90         return node->addr & PAGE_MASK;
  91 }
  92
  93 static unsigned long mmu_node_last(struct mmu_rb_node *node)
  94 {
  95         return PAGE_ALIGN(node->addr + node->len) - 1;
  96 }
  97
  98 int hfi1_mmu_rb_register(struct rb_root *root, struct mmu_rb_ops *ops)
  99 {
 100         struct mmu_rb_handler *handlr;
 101
 102         if (!ops->invalidate)
 103                 return -EINVAL;
 104
 105         handlr = kmalloc(sizeof(*handlr), GFP_KERNEL);
 106         if (!handlr)
 107                 return -ENOMEM;
 108
 109         handlr->root = root;
 110         handlr->ops = ops;
 111         INIT_HLIST_NODE(&handlr->mn.hlist);
 112         spin_lock_init(&handlr->lock);
 113         handlr->mn.ops = &mn_opts;
 114         spin_lock(&mmu_rb_lock);
 115         list_add_tail_rcu(&handlr->list, &mmu_rb_handlers);
 116         spin_unlock(&mmu_rb_lock);
 117
 118         return mmu_notifier_register(&handlr->mn, current->mm);
 119 }
 120
 121 void hfi1_mmu_rb_unregister(struct rb_root *root)
 122 {
 123         struct mmu_rb_handler *handler = find_mmu_handler(root);
 124         unsigned long flags;
 125
 126         if (!handler)
 127                 return;
 128
 129         /* Unregister first so we don't get any more notifications. */
 130         if (current->mm)
 131                 mmu_notifier_unregister(&handler->mn, current->mm);
 132
 133         spin_lock(&mmu_rb_lock);
 134         list_del_rcu(&handler->list);
 135         spin_unlock(&mmu_rb_lock);
 136         synchronize_rcu();
 137
 138         spin_lock_irqsave(&handler->lock, flags);
 139         if (!RB_EMPTY_ROOT(root)) {
 140                 struct rb_node *node;
 141                 struct mmu_rb_node *rbnode;
 142
 143                 while ((node = rb_first(root))) {
 144                         rbnode = rb_entry(node, struct mmu_rb_node, node);
 145                         rb_erase(node, root);
 146                         if (handler->ops->remove)
 147                                 handler->ops->remove(root, rbnode, NULL);
 148                 }
 149         }
 150         spin_unlock_irqrestore(&handler->lock, flags);
 151
 152         kfree(handler);
 153 }
 154
 155 int hfi1_mmu_rb_insert(struct rb_root *root, struct mmu_rb_node *mnode)
 156 {
 157         struct mmu_rb_handler *handler = find_mmu_handler(root);
 158         struct mmu_rb_node *node;
 159         unsigned long flags;
 160         int ret = 0;
 161
 162         if (!handler)
 163                 return -EINVAL;
 164
 165         spin_lock_irqsave(&handler->lock, flags);
 166         hfi1_cdbg(MMU, "Inserting node addr 0x%llx, len %u", mnode->addr,
 167                   mnode->len);
 168         node = __mmu_rb_search(handler, mnode->addr, mnode->len);
 169         if (node) {
 170                 ret = -EINVAL;
 171                 goto unlock;
 172         }
 173         __mmu_int_rb_insert(mnode, root);
 174
 175         if (handler->ops->insert) {
 176                 ret = handler->ops->insert(root, mnode);
 177                 if (ret)
 178                         __mmu_int_rb_remove(mnode, root);
 179         }
 180 unlock:
 181         spin_unlock_irqrestore(&handler->lock, flags);
 182         return ret;
 183 }
 184
 185 /* Caller must hold handler lock */
 186 static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *handler,
 187                                            unsigned long addr,
 188                                            unsigned long len)
 189 {
 190         struct mmu_rb_node *node = NULL;
 191
 192         hfi1_cdbg(MMU, "Searching for addr 0x%llx, len %u", addr, len);
 193         if (!handler->ops->filter) {
 194                 node = __mmu_int_rb_iter_first(handler->root, addr,
 195                                                (addr + len) - 1);
 196         } else {
 197                 for (node = __mmu_int_rb_iter_first(handler->root, addr,
 198                                                     (addr + len) - 1);
 199                      node;
 200                      node = __mmu_int_rb_iter_next(node, addr,
 201                                                    (addr + len) - 1)) {
 202                         if (handler->ops->filter(node, addr, len))
 203                                 return node;
 204                 }
 205         }
 206         return node;
 207 }
 208
 209 /* Caller must *not* hold handler lock. */
 210 static void __mmu_rb_remove(struct mmu_rb_handler *handler,
 211                             struct mmu_rb_node *node, struct mm_struct *mm)
 212 {
 213         unsigned long flags;
 214
 215         /* Validity of handler and node pointers has been checked by caller. */
 216         hfi1_cdbg(MMU, "Removing node addr 0x%llx, len %u", node->addr,
 217                   node->len);
 218         spin_lock_irqsave(&handler->lock, flags);
 219         __mmu_int_rb_remove(node, handler->root);
 220         spin_unlock_irqrestore(&handler->lock, flags);
 221
 222         if (handler->ops->remove)
 223                 handler->ops->remove(handler->root, node, mm);
 224 }
 225
 226 struct mmu_rb_node *hfi1_mmu_rb_search(struct rb_root *root, unsigned long addr,
 227                                        unsigned long len)
 228 {
 229         struct mmu_rb_handler *handler = find_mmu_handler(root);
 230         struct mmu_rb_node *node;
 231         unsigned long flags;
 232
 233         if (!handler)
 234                 return ERR_PTR(-EINVAL);
 235
 236         spin_lock_irqsave(&handler->lock, flags);
 237         node = __mmu_rb_search(handler, addr, len);
 238         spin_unlock_irqrestore(&handler->lock, flags);
 239
 240         return node;
 241 }
 242
 243 struct mmu_rb_node *hfi1_mmu_rb_extract(struct rb_root *root,
 244                                         unsigned long addr, unsigned long len)
 245 {
 246         struct mmu_rb_handler *handler = find_mmu_handler(root);
 247         struct mmu_rb_node *node;
 248         unsigned long flags;
 249
 250         if (!handler)
 251                 return ERR_PTR(-EINVAL);
 252
 253         spin_lock_irqsave(&handler->lock, flags);
 254         node = __mmu_rb_search(handler, addr, len);
 255         if (node)
 256                 __mmu_int_rb_remove(node, handler->root);
 257         spin_unlock_irqrestore(&handler->lock, flags);
 258
 259         return node;
 260 }
 261
 262 void hfi1_mmu_rb_remove(struct rb_root *root, struct mmu_rb_node *node)
 263 {
 264         struct mmu_rb_handler *handler = find_mmu_handler(root);
 265
 266         if (!handler || !node)
 267                 return;
 268
 269         __mmu_rb_remove(handler, node, NULL);
 270 }
 271
 272 static struct mmu_rb_handler *find_mmu_handler(struct rb_root *root)
 273 {
 274         struct mmu_rb_handler *handler;
 275
 276         rcu_read_lock();
 277         list_for_each_entry_rcu(handler, &mmu_rb_handlers, list) {
 278                 if (handler->root == root)
 279                         goto unlock;
 280         }
 281         handler = NULL;
 282 unlock:
 283         rcu_read_unlock();
 284         return handler;
 285 }
 286
 287 static inline void mmu_notifier_page(struct mmu_notifier *mn,
 288                                      struct mm_struct *mm, unsigned long addr)
 289 {
 290         mmu_notifier_mem_invalidate(mn, mm, addr, addr + PAGE_SIZE);
 291 }
 292
 293 static inline void mmu_notifier_range_start(struct mmu_notifier *mn,
 294                                             struct mm_struct *mm,
 295                                             unsigned long start,
 296                                             unsigned long end)
 297 {
 298         mmu_notifier_mem_invalidate(mn, mm, start, end);
 299 }
 300
 301 static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
 302                                         struct mm_struct *mm,
 303                                         unsigned long start, unsigned long end)
 304 {
 305         struct mmu_rb_handler *handler =
 306                 container_of(mn, struct mmu_rb_handler, mn);
 307         struct rb_root *root = handler->root;
 308         struct mmu_rb_node *node, *ptr = NULL;
 309         unsigned long flags;
 310
 311         spin_lock_irqsave(&handler->lock, flags);
 312         for (node = __mmu_int_rb_iter_first(root, start, end - 1);
 313              node; node = ptr) {
 314                 /* Guard against node removal. */
 315                 ptr = __mmu_int_rb_iter_next(node, start, end - 1);
 316                 hfi1_cdbg(MMU, "Invalidating node addr 0x%llx, len %u",
 317                           node->addr, node->len);
 318                 if (handler->ops->invalidate(root, node)) {
 319                         __mmu_int_rb_remove(node, root);
 320                         if (handler->ops->remove)
 321                                 handler->ops->remove(root, node, mm);
 322                 }
 323         }
 324         spin_unlock_irqrestore(&handler->lock, flags);
 325 }